Mnemosyne: Mnemosyne no Musume-tachi centers on Rin Asougi, an immortal private investigator who has lived through countless lifetimes.
The story follows her as she navigates a world where her immortality makes her a target.
In 1990, Rin becomes involved with Kouki Maeno, a man with fragmented memories, leading her down a dangerous path.
She uncovers secrets about Kouki and confronts a mysterious enemy who threatens her existence, promising a potentially permanent end to her immortality.
The anime explores themes of immortality, identity, and the cost of living forever, all while Rin fights to survive against those who seek to destroy her.